US1843413A - Liquation of copper - Google Patents

Description

Feb. 2, 1932; J. o. BETTERTON 1,

'LIQUATION OF COPPER Filed May 25, 1928 BLAST FURNACE L EAD BULL/0N REMOVED HEATED TO 7857'.

COOLED T0 550V"? APPROXIMATELY 25% BECOMES FROZEN LIQUID PORT/0N TflPPED 0 501.10 PORT/0N REMELTED. A5 REF/NED Pb L CONTAINS Cu /N c EUTECT/C PROPORTION To MELT/N6 P0 NT 0/ LE/ID. Dfi055 FORMED.

LIQUID CON TA/NS 0Ross REMOVED L REMAINING Cu.

RETURNED T0 FURNACE FOR cu RECOVERY ADDED TO MORE BULL/0N FOR FURTHER TREATMENT.

INVENTOR.

f 0% BY M0 7:1.M'

ATTORNEY Patented Feb. 2, 1932 UNITED STATES PATENT VOFFICE mssn oA'rMAN BEr'rEaroN, or OMAHA, NEBRASKA, ASSIGNOR :ro AMERICAN smmrrme & nnrmme comrAmr, or NEW YORK, N. Y., A coRroRA'rIoN or NEW JERSEY LIQUATIoN 'or corr in Application filed Kay 23, 1928. Serial No. 279,880.

This invention relates to lead refining and more particularly to a new and improved process of removing copper from lead bul-' lion.

In accordance with the present invention, copper and various other impurities are removed from lead bullion by selective freezing whereby the liquid portion comprises lead of a suflicient degree of purity for certain commercial purposes. Skimming is eliminated by tapping the molten metal after the Impurities have been selectively frozen out and allowing the metal to run into suitable containers for further use. The impuritiesare then remelted and separately recovered.

The invention also consists in certain new and original features of construction and combinations of parts hereinafter set forth and claimed.

' Although the novel features which are believed to be characteristic of this invention will be particularly pointed out in the claims appended hereto, the invention itself, as to its objects and advantages, the mode of its operation and the manner of its organization may be better understood by referring to the following description takenin connection with the accompanying drawingforming a part thereof, in which The figure is a flow sheet representing one method of practicing the invention.

In the following description and in the claims parts will be identified by specific 3 names for convenience, but they are intended a small portion of the lead to solidify. line to thevheat radiation at the surface and sides of the bath these portions will become solid I lead, and may be eliminated from the remaining liquid portion down to a degree correspondmg substantially to their eutectic with lead. In the case of copper substantially .065% will remain, the balance being con-,.

tained in the frozen portion. This percentage is sufficiently low to enable the lead to be employed for commercial purposes without further refining. Thev liquid portion, which comprises most of the lead, may then be tapped oif and cast into bars for the market.

The solid portion containing the greater percentage of copper is then remelted and again cooled substantially to the freezing point of lead. The solid portion will contain a large proportion of the remaining copper and may be returned to the furnace for further refining, or may be allowed to remain in the kettle until a suflicient amount accumulates, when it may be drossed in the usual manner, and th'edross returned to the furnace. The liquid portion is added to the bullion which is taken from the smelting furnace and is further treated for copper removal in accordance with the foregoing steps.

bullion containing 255% copper was heated Considering a specific example, a mass of to a temperature of 785 degrees F. and then cooled to a temperature of substantially 580 degrees F. At this temperature about 25% of the metal was frozen and contained the major portion of the various impurities. The remaining molten-bullion contained substantially 065% copper, which is the eutectic of copper and lead. This metal was tapped and marketed. The frozen portion, or crust, was then remelted and afterfurther cooling, during which metallic dross was formed thereon, was tapped and added to further quantities of blast furnace bul lion and again treated for copper removal. The metallic dross, which contained 31.73% of the copper originally present, was then returned to the blast furnace and treated for copper removal. This dross forms the outlet of copper for the entire system, whereas the tapped metal, containing 065% of copper, is the outlet of lead. After the process has been placed in operation, it automatically stabilizes with an outlet of refined lead at the first tap and an outlet of copper at the final dross. Obviously, the percentages given above may vary in accordance with the particular bullion under treatment. Certain figures have been set forth by way of illustration, only.

Referring to the mechanical features of the process, the bullion from the blast furnacc is collected in a kettle provided, preferably with a tap at .the bottom thereof. When filled, the kettle is allowed to cool to a point approximately at the melting point of lead and is maintained in this condition until some 25% of the original metal has become frozen. The remaining 75% of the original bullion is tapped as a bullion containing approximately .06 5%- copper and used for moulding and other purposes where it will require no further special treatment for copper removal.

The frozen portion comprising approximately 25% of the original bullion is remelted and is pumped to another receiving kettle. It is then melted and treated for the removal of a copper dross which is the outlet for copper of the entire system. The remaining liquid is then pumped to another receiving kettle, is further cooled to reduce the copper content to a point similar to that of the original bullion and is then treated with further quantities of bullion from the blast furnace. The process stabilizes with an outlet for copper in the dresses at one point and an outlet for bullion suitable refining operations at another point. The quantity of material treated may be reduced by employing mixing machines for drying the various, dresses and reducing the volume thereof before returning the same to the furnace. l

The invention has been specifically described for the sake of clearness as applied to lead bullion. It is. however. applicable to the refining of other metals. such as antimonial lead. This la'tter metal has been refined by the above mentioned proc ess to an :n'erage of .087r copper. which was then further diluted with refined lead and used as battery plate alloy.

In carrying out the process it not essential to freeze out any particular proportion of lead after the mass of bullion has for reached the freezing point of leadf In operating on a commercial scale it was found preferable, however, to allow approximately 25% of the material to become frozen since the heat radiation from the surface of the bath rendered the maintenance of an even temperature extremely difficult. The lead was therefore allowed to freeze on the surface and around the sides of the kettle in order to permit the central portion of the bath to reach the desired temperature.

Although certain novel features of the invention have been shown and described and are pointed out in the annexed claims, it will be understood that various omissions, substitutions and changes in the several steps of the process and in its operation may be made by those skilled in the art without departing from the spirit of the invention.

lVhat is claimed is:

1. The process of refining lead bullion for the removal of copper down to appoint corresponding to the eutectic of copper and lead which comprisesheating said bullion to a temperature substantially above the melting point of'lead and cooling the top and sides of the mass sufiiciently below the eutectic temperature to cause a substantial portion of the bullion at the top of the sides to solidify and to bring the temperature of the interior to substantially the eutectic temperature, whereby the copper in the liquid portion is reduced to the eutectic'proportion and then removing the liquid from below the solid .portion, re-melting said solid portion and said bullion to a temperature of approxim ately 7 85 F., whereby the entire mass becomes liquid and over-cooling the bullion at the surface and sides to a. temperature of approximately 580 F. whereby the interior is cooled to substantially the'eutectictemperature of lead and copper and approximately 25% of the metal becomes frozen, removing the liquid portion which contains copper in substantially the eutectic proportion, re-melting. the solid portion and cooling the same to the melting point of lead to produce a dross containing substantial quantities of copper, removing the dress and returning the liquid for re-treatment in accordance with the above pro Jess. y i

3. The process of refining lead bullion for the removal of copper tothe eutecticpropon tion which comprises heating said bullion to a temperature above the melting point thereof and allowing the same to slowly cool from the surface and sides to a temperature at which approximately 25% thereof becomes frozen, whereby the liquid portion contains a percentage of copper corresponding to the eutectic, removing the liquid from below the solid portion remelting and further decreasing the copper content of said solid portion by progressively cooling to form a copper dross, removing the dross and returning the liquid for treatment with further quantities of bullion in accordance with the above process.

In testimony whereof I have hereunto set my hand.

JESSE OATMAN BETTERTON.

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